全文获取类型
收费全文 | 5839篇 |
免费 | 539篇 |
国内免费 | 3篇 |
出版年
2023年 | 21篇 |
2022年 | 42篇 |
2021年 | 113篇 |
2020年 | 77篇 |
2019年 | 103篇 |
2018年 | 125篇 |
2017年 | 101篇 |
2016年 | 159篇 |
2015年 | 277篇 |
2014年 | 342篇 |
2013年 | 392篇 |
2012年 | 504篇 |
2011年 | 452篇 |
2010年 | 317篇 |
2009年 | 318篇 |
2008年 | 398篇 |
2007年 | 402篇 |
2006年 | 334篇 |
2005年 | 319篇 |
2004年 | 315篇 |
2003年 | 331篇 |
2002年 | 262篇 |
2001年 | 58篇 |
2000年 | 46篇 |
1999年 | 57篇 |
1998年 | 60篇 |
1997年 | 47篇 |
1996年 | 27篇 |
1995年 | 27篇 |
1994年 | 18篇 |
1993年 | 24篇 |
1992年 | 33篇 |
1991年 | 27篇 |
1990年 | 21篇 |
1989年 | 19篇 |
1988年 | 13篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 12篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1976年 | 14篇 |
1975年 | 11篇 |
1973年 | 7篇 |
1971年 | 14篇 |
排序方式: 共有6381条查询结果,搜索用时 15 毫秒
921.
Sadeq Alzubik Belkair Christophe Mazzia Alain Pasquet 《Biocontrol Science and Technology》2018,28(9):823-836
It is well known that spiders are present in high numbers in orchards and may contribute to biocontrol. Some recent studies in central Europe further showed that some spiders are active year-round and consume pests even in winter. Using cardboard traps laid every two weeks, we carried out a survey to determine which spider and earwig species are active from September to May in an experimental, pesticide-free, apple orchard under a Mediterranean climate. We observed that spider activity was never completely absent. The structure of the spider communities showed a marked seasonality in three periods (so-called ‘autumn’, ‘winter’ and ‘spring’). Only two spider genera, Philodromus and Trachelas, were highly active in winter (percentage of catches during this season above 40%) and six others (Lathys, Clubiona, Gnaphosa, Theridion, Phrurolithus) had moderate activity (between 20 and 40%). The two earwig species had different patterns of winter activity with Forficula auricularia almost absent whereas F. pubescens was moderately active on trees. Spider community abundance, diversity and evenness significantly decreased between autumn and winter and remained low in the following spring probably because the attractiveness of the traps is much lower at this time of year due to mild temperatures and the presence of leaves on the trees. Winter-active spiders could contribute to pest biocontrol during the cold season and we advocate that the use of broad-spectrum pesticides at the end of winter, as classically applied in orchards, may be counter-productive for pest control. 相似文献
922.
Gilles Ouvry Franck Bihl Claire Bouix-Peter Olivier Christin Claire Defoin-Platel Sophie Deret Christophe Feret David Froude Feriel Hacini-Rachinel Craig S. Harris Catherine Hervouet Guillaume Lafitte Anne-Pascale Luzy Branislav Musicki Danielle Orfila Veronique Parnet Coralie Pascau Jonathan Pascau Laurent F. Hennequin 《Bioorganic & medicinal chemistry letters》2018,28(8):1269-1273
Progress in the identification of suitable RORγ inverse agonists as clinical candidates has been hampered by the high lipophilicity that seems required for high potency on this nuclear receptor. In this context, we decided to focus on the replacement of the hydroxymethyl group found on known modulators to determine if more polarity could be tolerated in this position. SAR of the replacement of this moiety is presented in this article leading to the identification of sulfoximine derivatives as potent modulators with pharmacological activity in the in vivo mouse Imiquimod psoriasis model. 相似文献
923.
924.
Stefanie Wagner Frédéric Lagane Andaine Seguin‐Orlando Mikkel Schubert Thibault Leroy Erwan Guichoux Emilie Chancerel Inger Bech‐Hebelstrup Vincent Bernard Cyrille Billard Yves Billaud Matthias Bolliger Christophe Croutsch Katarina Čufar Frédérique Eynaud Karl Uwe Heussner Joachim Köninger Fabien Langenegger Frédéric Leroy Christine Lima Nicoletta Martinelli Garry Momber André Billamboz Oliver Nelle Antoni Palomo Raquel Piqué Marianne Ramstein Roswitha Schweichel Harald Stäuble Willy Tegel Xavier Terradas Florence Verdin Christophe Plomion Antoine Kremer Ludovic Orlando 《Molecular ecology》2018,27(5):1138-1154
Reconstructing the colonization and demographic dynamics that gave rise to extant forests is essential to forecasts of forest responses to environmental changes. Classical approaches to map how population of trees changed through space and time largely rely on pollen distribution patterns, with only a limited number of studies exploiting DNA molecules preserved in wooden tree archaeological and subfossil remains. Here, we advance such analyses by applying high‐throughput (HTS) DNA sequencing to wood archaeological and subfossil material for the first time, using a comprehensive sample of 167 European white oak waterlogged remains spanning a large temporal (from 550 to 9,800 years) and geographical range across Europe. The successful characterization of the endogenous DNA and exogenous microbial DNA of 140 (~83%) samples helped the identification of environmental conditions favouring long‐term DNA preservation in wood remains, and started to unveil the first trends in the DNA decay process in wood material. Additionally, the maternally inherited chloroplast haplotypes of 21 samples from three periods of forest human‐induced use (Neolithic, Bronze Age and Middle Ages) were found to be consistent with those of modern populations growing in the same geographic areas. Our work paves the way for further studies aiming at using ancient DNA preserved in wood to reconstruct the micro‐evolutionary response of trees to climate change and human forest management. 相似文献
925.
926.
Céline Guien Gaëlle Blandin Pauline Lahaut Benoît Sanson Katia Nehal Sitraka Rabarimeriarijaona Rafaëlle Bernard Nicolas Lévy Sabrina Sacconi Christophe Béroud 《Orphanet journal of rare diseases》2018,13(1):218
Background
Facioscapulohumeral muscular dystrophy is a rare inherited neuromuscular disease with an estimated prevalence of 1/20,000 and France therefore harbors about 3000 FSHD patients. With research progress and the development of targeted therapies, patients’ identification through registries can facilitate and improve recruitment in clinical trials and studies.Results
The French National Registry of FSHD patients was designed as a mixed model registry involving both patients and physicians, through self-report and clinical evaluation questionnaires respectively, to collect molecular and clinical data. Because of the limited number of patients, data quality is a major goal of the registry and various automatic data control features have been implemented in the bioinformatics system. In parallel, data are manually validated by molecular and clinical curators. Since its creation in 2013, data from 638 FSHD patients have been collected, representing about 21% of the French FSHD population. The mixed model strategy allowed to collect 59.1% of data from both patients and clinicians; 26 and 14.9% from respectively patients and clinicians only. With the identification of the FSHD1 and FSHD2 forms, specific questionnaires have been designed. Though FSHD2 patients are progressively included, FSHD1 patients still account for the majority (94.9%). The registry is compatible with the FAIR principles as data are Findable, Accessible and Interoperable. We thus used molecular standards and standardized clinical terms used by the FILNEMUS French network of reference centers for the diagnosis and follow-up of patients suffering from a rare neuromuscular disease. The implemented clinical terms mostly map to dictionaries and terminology systems such as SNOMED-CT (75% of terms), CTV3 (61.7%) and NCIt (53.3%). Because of the sensitive nature of data, they are not directly reusable and can only be accessed as aggregated data after evaluation and approval by the registry oversight committee.Conclusions
The French National Registry of FSHD patients belongs to a national effort to develop databases, which should now interact with other initiatives to build a European and/or an international FSHD virtual registry for the benefits of patients. It is accessible at www.fshd.fr and various useful information, links, and documents, including a video, are available for patients and professionals.927.
Trans‐species synthetic gene design allows resistance pyramiding and broad‐spectrum engineering of virus resistance in plants 下载免费PDF全文
Anna Bastet Baptiste Lederer Nathalie Giovinazzo Xavier Arnoux Sylvie German‐Retana Catherine Reinbold Véronique Brault Damien Garcia Samia Djennane Sophie Gersch Olivier Lemaire Christophe Robaglia Jean‐Luc Gallois 《Plant biotechnology journal》2018,16(9):1569-1581
To infect plants, viruses rely heavily on their host's machinery. Plant genetic resistances based on host factor modifications can be found among existing natural variability and are widely used for some but not all crops. While biotechnology can supply for the lack of natural resistance alleles, new strategies need to be developed to increase resistance spectra and durability without impairing plant development. Here, we assess how the targeted allele modification of the Arabidopsis thaliana translation initiation factor eIF4E1 can lead to broad and efficient resistance to the major group of potyviruses. A synthetic Arabidopsis thaliana eIF4E1 allele was designed by introducing multiple amino acid changes associated with resistance to potyvirus in naturally occurring Pisum sativum alleles. This new allele encodes a functional protein while maintaining plant resistance to a potyvirus isolate that usually hijacks eIF4E1. Due to its biological functionality, this synthetic allele allows, at no developmental cost, the pyramiding of resistances to potyviruses that selectively use the two major translation initiation factors, eIF4E1 or its isoform eIFiso4E. Moreover, this combination extends the resistance spectrum to potyvirus isolates for which no efficient resistance has so far been found, including resistance‐breaking isolates and an unrelated virus belonging to the Luteoviridae family. This study is a proof‐of‐concept for the efficiency of gene engineering combined with knowledge of natural variation to generate trans‐species virus resistance at no developmental cost to the plant. This has implications for breeding of crops with broad‐spectrum and high durability resistance using recent genome editing techniques. 相似文献
928.
Ok‐Ryul Song Christophe J Queval Raffaella Iantomasi Vincent Delorme Sabrina Marion Romain Veyron‐Churlet Elisabeth Werkmeister Michka Popoff Isabelle Ricard Samuel Jouny Nathalie Deboosere Frank Lafont Alain Baulard Laurent Marsollier Eik Hoffmann Priscille Brodin 《EMBO reports》2018,19(1):29-42
The interaction of Mycobacterium tuberculosis (Mtb) with pulmonary epithelial cells is critical for early stages of bacillus colonization and during the progression of tuberculosis. Entry of Mtb into epithelial cells has been shown to depend on F‐actin polymerization, though the molecular mechanisms are still unclear. Here, we demonstrate that mycobacterial uptake into epithelial cells requires rearrangements of the actin cytoskeleton, which are regulated by ADP‐ribosylation factor 1 (Arf1) and phospholipase D1 (PLD1), and is dependent on the M3 muscarinic receptor (M3R). We show that this pathway is controlled by Arf GTPase‐activating protein 1 (ArfGAP1), as its silencing has an impact on actin cytoskeleton reorganization leading to uncontrolled uptake and replication of Mtb. Furthermore, we provide evidence that this pathway is critical for mycobacterial entry, while the cellular infection with other pathogens, such as Shigella flexneri and Yersinia pseudotuberculosis, is not affected. Altogether, these results reveal how cortical actin plays the role of a barrier to prevent mycobacterial entry into epithelial cells and indicate a novel role for ArfGAP1 as a restriction factor of host–pathogen interactions. 相似文献
929.
The role of ungulates in nowadays temperate forests. A response to Fløjgaard et al. (DOI:10.1111/gcb.14029) 下载免费PDF全文
930.
Vincent Boulanger Jean‐Luc Dupouey Frédéric Archaux Vincent Badeau Christophe Baltzinger Richard Chevalier Emmanuel Corcket Yann Dumas Françoise Forgeard Anders Mårell Pierre Montpied Yoan Paillet Jean‐François Picard Sonia Saïd Erwin Ulrich 《Global Change Biology》2018,24(2):e485-e495
Large wild ungulates are a major biotic factor shaping plant communities. They influence species abundance and occurrence directly by herbivory and plant dispersal, or indirectly by modifying plant‐plant interactions and through soil disturbance. In forest ecosystems, researchers’ attention has been mainly focused on deer overabundance. Far less is known about the effects on understory plant dynamics and diversity of wild ungulates where their abundance is maintained at lower levels to mitigate impacts on tree regeneration. We used vegetation data collected over 10 years on 82 pairs of exclosure (excluding ungulates) and control plots located in a nation‐wide forest monitoring network (Renecofor). We report the effects of ungulate exclusion on (i) plant species richness and ecological characteristics, (ii) and cover percentage of herbaceous and shrub layers. We also analyzed the response of these variables along gradients of ungulate abundance, based on hunting statistics, for wild boar (Sus scrofa), red deer (Cervus elaphus) and roe deer (Capreolus capreolus). Outside the exclosures, forest ungulates maintained higher species richness in the herbaceous layer (+15%), while the shrub layer was 17% less rich, and the plant communities became more light‐demanding. Inside the exclosures, shrub cover increased, often to the benefit of bramble (Rubus fruticosus agg.). Ungulates tend to favour ruderal, hemerobic, epizoochorous and non‐forest species. Among plots, the magnitude of vegetation changes was proportional to deer abundance. We conclude that ungulates, through the control of the shrub layer, indirectly increase herbaceous plant species richness by increasing light reaching the ground. However, this increase is detrimental to the peculiarity of forest plant communities and contributes to a landscape‐level biotic homogenization. Even at population density levels considered to be harmless for overall plant species richness, ungulates remain a conservation issue for plant community composition. 相似文献